Higher halophenoxy benzoic acid esters

ABSTRACT

Alkyl (C4-C12), cycloalkyl (C3-C8), and unsaturated hydrocarbyl (C3-C10) esters of 2-nitro-5-(halophenoxy)benzoic acids comprise a class of compounds that are highly effective pre- and postemergence herbicides.

United States Patent [191 I Theissen HIGHER HALOPHENOXY BENZOIC ACID ESTERS [75] Inventor: Robert J. Theissen, Westfield, NJ.

[73] Assignee: Mobil Oil Corporation, New York,

[22] Filed: June 7, 1974 I21 Appl. No.: 477,233

[52] US. Cl. 260/471 R; 71/111 [51] Int. Cl. C07C 79/46 [58] Field of Search 260/471 R [56] References Cited UNITED STATES PATENTS 3,798,276 3/1974 Bayer et a] 260/471 R Sept. 23, 1975 Primary ExaminerJames A. Patten Assistant ExaminerL. A. Thaxton Attorney, Agent, or FirmCharles A. Huggett; Hastings S. Trigg [57] ABSTRACT 7 Claims, No Drawings HIGHER HALOPHENOXY BENZOIC ACID ESTERS BACKGROUND OF THE INVENTION l. Field of the Invention This invention is concerned with certain phenoxybenzoic acid esters and their use as herbicides.

2. Description of the Prior Art In U.S. Pat. No. 3,652,645. there is disclosed alkyl (C,C;;) esters of 2-nitro-5-(halophenoxy) benzoic acids as herbicides. Under some early-season weather conditions, especially when treated soil is splashed onto the lower leaves. contact injury may be seen. On soybeans. this may appear as erinkling of the lower leaves of young plants. On com, the effect may be a discolored band on the lower blades. Occasionally. stunting may be observed. Crop injury under high soil moisture levels may not appear for 2 or 3 weeks and is temporary. The crop will grow out of it and yields are not adversely affected.

The transverse (chlorotie) band on com blades presents a phytotoxic appearance that is evident on the plant throughout the early growing season. Such appearance. although not adversely affecting yield, can

be offensive to many growers and could dissuade them from using an otherwise effective herbicide. It is the discovery of this invention that the alkyl (C C and cycloalkyl (C -C esters. do not appear to give the phytotoxic appearance evidenced by the alkyl esters disclosed in U.S. Pat. No. 3,652,645.

SUMMARY OF THE INVENTION This invention provides herbicidal compounds having the formula:

COOR

DESCRIPTION OF SPECIFIC EMBODIMENTS The compounds of this invention are readily prepared by reacting a 2-nitro-5-halophenoxybenzoyl chloride with the appropriate alcohol in the presence of a tertiary amine acceptor for HC such as triethylamine and pyridine. The benzoyl chloride is prepared, in a first step by the Ullmann ether synthesis reaction between the alkali metal (Na, K) salt of a halophenol and a S-halo (Cl, Br)-2-nitrobenzoic acid. methyl ester, or salt. The 2-nitro-5-(halophenoxy')benzoic acid is then converted to the acyl chloride by well known methods, such as by reacting it with PCI PCI or SOCl The salt (Na) of the benzoic acid is converted to the acyl halide by well known methods, such as by reacting it with PCl PC1 POC1 or SOCI If the methyl ester is used in Ullmann ether synthesis, it is hydrolyzed to the acid, which is converted to the acyl halide as aforedescribed. Such procedure is described and illustrated in U.S. Pat. No. 3.812.284. which is hereby incorporated herein by reference thereto. The S-halo- 2'nitrobenzoic acid is readily prepared by nitrating a m-halotoluene. followed by oxidation of the methyl group well-known procedures.

The csterifying alcohol. i.e.. the source of the R" group in the structural formula of the compounds of this invention. is an alkanol (C C,- a cycloalkanol (C -C or an unsaturated hydrocarbyl alcohol (Cg- 10). The alkanol can have a normal (straight) chain or it can have a branched chain. The cycloalltanol is a saturated carbocyclic alcohol having between 3 and 8 carbon atoms. It can have methyl substituents on the ring. The unsaturated hydrocarbyl alcohol contains a vinyl unsaturation or an acetylenic (-C C) unsaturation. It can also contain a cyclohexyl group. Typical esterifying R groups contemplated are illustrated in the specific working examples.

SATURATED HYDROCARBYL ESTERS The following example illustrates the preparation of a compound of this invention. wherein R is saturated. and demonstrates a method for product recovery.

EXAMPLE I Cyclohexyl 5-( 2', 4-dichlorophenoxy )-2-nitrobenzoate To a stirred solution of cyclohexanol (l.05g.. 0.0l05

mole) and triethylamine (l.l0g.. 0.011 mole) in tolu- EXAMPLES 2 through 18 2. n-Pentyl 5-12,

4'-Dichlorophenoxy)-2- nitrobenzoate. oil.

3. n-Butyl 5-( 2 ',4'-Dichlorophenoxy)-2- nitrobenzoate. oil. 4. sec-Butyl 5-( 2',4'-dichlorophenoxy )-2- nitrobenzoate. oil. 5. iso-Butyl --'5-(2, nitrobenzoate, oil.

4-Dichlorophenoxy )-2- 6. Dodecyl; 5-(2',4-Dichlorophenoxy)-2- nitrobenzoate, oil.

7. 2-Octyl 5-(2,4-Dichlorophenoxy)-2- nitrobenzoate, oil.

8. Isoamyl 5-(2',4'-Dichlorophenoxy)-2- nitrobenzoate, oil.

9. n-Octyl 5-(2',4-Dichlorophenoxy)-2- nitrobenzoate, oil.

3 4 l0. t-Butyl 2'.4'-Dichlorophenoxy)-2- greenhouse trays. Pots for the pre-emergence phase are nitrobenzoate. oil. seeded 1 day before treatment. l l. Z-Decyl 5-( 2',4Dichlorophenoxy)-2- Planting dates for the post-emergence phase are varnitrobenzoate. oil. ied so that all the seedlings will reach the desired stage 12. Z-Heptyl 5-(2,4-Dichlorophenoxy)-2- 5 of development simultaneously. The proper stage of nitrobenzoate. oil. seedling development for treatment in the post- 13. Z-Nonyl 5-(2'.4'-Dichlorophenoxy)-2- emergence phase is as follows:

nitrobenzoate. oil. l4. nPentyl 2-Nit'ro-5-t2'.4'.0'-trichlorophenoxy)- (ERASSES: 2 inches in height bmmdt ll) mower iiixnwi-iiit). i or 2 true l1.".1\t.s \isihle l5. Z-Oetyl 2-Nitro-:-(2'.4.6-trichlorophenoxy)- \'i-1i.\' .'r Lia-wa- 'IlRNIPS: above erupt-aims bcnzoatfl Oil COTTON: first true leaf l inch in I I length: e\paiided cotyledons l6. CYClOl'lCXYl 2- lU'O-5-(- CORN; 3 inches-4 inches in height BEANS: primary lea\ es expanded; growing trichlorophenoxy) benzoate. oil. 17. Z-Octyl 5-(2,4'-Dichloro-o-fluorophenoxy)-2- l nitrobenzoate. oil. l8. Cyclohexyl 5-(2,4-Dichloro-6-fluorophenoxy)- Method of Treatment Z-nitrobenzoate. oil.

point at primary leaf node.

Spray applications are made in a hood containing a m movable belt and fixed spray nozzle. For passage HERBICIDAL EFFECTIVENESS through the spray hood. one pot of each species (pre- I I 1 emergence phase) is placed on the forward half of a Muhod Pmplgmng Spcclw wooden flat and one pot of established plants (postemergence phase) is placed on the rear half of the flat.

cmhgmss mummmmumum Treatments are moved to the greenhouse after spray- Johnson grass Suim HHILIR'IIXL' ing. Watering during the observation period is applied Barnyard grass Iii'liilimli/mi crm-gulli on] b s.11min.igdtion Field hindweed ('uliro/vu/uw urre/ixis y i i Velvet leiii' Alum/mi I/It'Up/H'luli Compounds are screened initially at a rate of applica- Turni Urum i xp. tion equivalent to four to eight pounds per acre. Two Cotton (im;v \-pliini llflX/HIIIH i'ur.

DPL Smumh leaf 30 weeks atter treatment the preand post-emergence per Corn Zvu M n var. l n B n cent in ury is visually rated. Subsequent testing can be carried out at 2.l and 0.3 pounds per acre.

Black \alentine 4 A Herhicidal testing of the compounds oi Examples l through 18 showed the results (i control) set forth in Table l. A blank indicates not testedv The plants are tabulated using the following abgreYiations:

All crop and weed species are planted individually in 3 3 inch plastic pots containing potting soil. Four seeds of each of cornv cotton, and snapbeans are seeded to a depth equal to the diameter of the seed. All other specmhgmss mi YL cies are surface seeded and sprinkled with screened soil Johnson grass Turnip T1 in an amount sufficient to cover the seeds. lmmcdiately -10 g'g mii fl after planting, all pots are watered by sub'irrigation in Bean BN TABLE I PRE/POST-EMERGENCE GRASSES BROADLEAVES CROPS EXAMPLE LBSJACRE CG JG BG BW VL TP CT CN BN 1. 8 0/0 0/ 0/ l00/- 90/ 100/90 02/30 0/ 0/90 4 0/0 0/ 0/ 40/ 70/-- 100/90 20/20 0/- 0/ l 00 1 0/0 0/ 0/- 0/ 0/ 50/60 0/70 0/ 0/l00 A 0/0 0/- 0/ 0/ 0/ 40/50 0/90 0/ 0/80 2. 8 0/0 0/ 0/ 70/90 0/70 0/- 0/ 4 40/0 ZO/ 0/ 30/ 20/- 40/90 0/60 0/ 0/60 4. 8 0/0 0/ 0/ 0/ 30/ 90/ l 00 0/70 0/- 0/ 4 70/0 30/ 0/ 0/- 70/ 90/60 0/30 01- 0/60 I l 8 0/40 0/- 0/ 0/ 70/ 80/100 30/l00 0/ ()l- 4 0/0 0/ 0/ 0/- 70/ 70/90 0/l00 0/- 0/100 12. 8 20/30 0/- 0/- 30/ 90/- 1 00 0/100 0/ 50/ i 00 4 0/20 0/ 0/ 20/ -70/ l 00/90 0/100 0/ ()/l 00 I3. 8 0/40 0/ 01- 40/ 70/ 90/ l 00 0/l00 0/ 50/l00 4 0/40 0/ 0/ 20/- 60/ 70/90 0/100 0/ 0/ l 00 I4. 8 20/20 20/ 20/- l 1001100 50/100 O/60 100/50 TABLE I-(ontinued PRE/POSTLEMERGENCE GRASSES BROADLEAVES CROPS EXAMPLE LBS/ACRE CG JG BG BW VL TP CT CN BN 2 50/80 --l l I- I 8 0/0 0/ 0/ 0/ 80/100 0/40 0/ 0/80 4 0/0 0/ 0/ 0/ 0/ l 00 -0/20 0/' 0/50 l6. 8 /40 0/ l00/ 100/90 0/90 0l 0/20 4 ()l- 0/ 0/ 40/- 90/100 0/90 0/. 0/20 2 0/ 0/ 0/ 0/ l -90/90 0/20 0/ 0/20 l7. 8 ()/3() ()l- 0/ 90/0 l00/l00 0/100 0/ 0/l00 4 0/0 0/ 0/ 40/ l 90/100 0/ l 00- 0/: 0/90 l8. 8 30/0 30/ 30/ 40/ l00/l00 0/l00 0/- 0/50 4 0/0 0/ '0/ 0/ l 90/ l 00 0/90 0/ 0/30 CORN LEAF PHY'IOTOXICI'I'Y COMPARISON 15 TABLE II TESTS v q v CORN LEAF PHYTOTOXICI'I'Y RATL'SGS Under ramtall conditions. anything more than a very s-st-vt-rc. 4-Motlerate. l-Mild. Z-Slight. lTrace. o-s'ontlight drizzle. the halophenoxyhenzoate ester herbicide EXAMPLE gll a' zf can readily be splashed into the whorl of young l-l0 3 l l 1 day old) corn seedlings. As the leaves grow out, the 3 phytotoxicity is observed as a chlorotic transverse hand across the leaf occurring at the previous point of 5 3-4 0-3 2 0 contact in the corn whorl. 25 0 In order to demonstrate the considerablyless phyto- 3 t toxic nature of C and greater alkyl esters as compared, I0 2-3 (1-2 1| 0-: a to C and less esters. the following greenhouse corn leal l3 3 0 toxicity tests were conducted. These tests served as a m screening procedure in simulating the phytotoxicity l5 0-I 0-l l 04 which occurs under actual field use conditions. Test Method Test solutions of the candidate com- "2 pounds were prepared as follows: 20 3-4 3 3 s 30 ppm 3.0 mg ot compound dissolved in 10.0 ml. i of acetone. This was then diluted with 90.0 ml. of dis- 33 5 4-5 tilled water to give a cloudy colloidal suspension. 0.3 ppm l.0 ml. of the 30 ppm solution was diluted with 99.0 ml. of distilled water. (This concentration level is UNSA'I'URATED HYDROCARBYL ESTERS about the averagewater solubility limit of the test com- Thc preparation of compounds of this invemkm PmmdS and it llkfily represents the actual field wherein the R group is unsaturated hydrocarbyl is illuscondition under which phytotoxici ty occurs.) trated in the tollowing examples. A typical product sep- One drop (ca. 0.05 ml.) of the test solution was then techmquc demonstratedplaced into the whorl of three (3) corn seedlings in the EXAMPLE 24 2-3 leaf stage. The phytotoxicity ratings shown in the following Table H were taken 3 days after treatment. 5 (2' 4' di hkj h y) 'z itr b t 5 Lxamples 19 3 are retercnce comparisons 01 C 1nd 0 To a Stirred 501mm of y (15g. 215 lowcl' mm mole) and tricthylamine (253g. 2.5 mole) in toluene EXAMPLE 1) I500 ml.) was added 5-(2',4'-dichlorophenoxy)-2- Methyl S-t 2.4'-Dichlorophenoxy )-Z-nitrobcnzoate. nitrobenzoyl chloride (500g. l.44mole A precipitate mp 835(. S; of triethylamine hydrochloride formed immediately EXAMPLE 20 f i and the reaction cxothermed to about 75C. The solun-Propyl 5-(Z'.4'-Dichloro henoxy)-2-nitrobenzoate tion was then heated at 60C. for 15 hours. The soluoil. tion was cooled and the precipitate filtered off. The fillixAMPLE 21 trate was freed of solvent and excess triethylamineto lsopropyl S-tI.Q4'-Dichlorophenoxy)-2-nitroben/oate 60 give a brown oily product (561g).

mp 55 m. IR. (neat): JCECH 3250. 46:0 1735 cm 1 EXAMPLE 22 Utilizing a similar procedure. the compounds in the Methyl Z-Nitro-S-t2'.4'.o'-trichloropehnoxy) following list were also prepared.

(X-)'. mp C EXAMPLES 2s through 36 EXAMPLE 23 Methyl S-t 2'.4'-Dichloro-(w-lluorophenoxy )-l-nitrobenzoate.

mp 68- 70C.

15. lropen-Z-yl nitrohenzoate. oil

26. Buten-Z-yl nitrobenzoate. oil

5-( 2 '.4-Dichlorophenoxy )-2- 27. 2-Methyl-3-buten-Z-yl S-t 2'.4- solid carriers include talc. bcntonite. diatomaceous Dichlorophenoxy)-2nitrobcnzoz1te. oil. earth. pyroplnllite. fullers earth. gypsum. flours de- 28. Propyn-Z-yl 5-( Z'.-1'-Dichlorophenoxv)Z- rived from cotton seeds and nut shells. and various natnitrobenzoate. oil. ural and synthetic clays having a pH not exceeding 2). 2-Meth vl3butyn-Z-yl 5-( 2'.-l- 5 about 9.5. Non-limiting examples of liquid carriers in- Dichlorophenoxy) Z- nitrobenzoate. oil clude \vater. organic solvents such as alcohols. ketones. 30. l-Methyl-l ethylpropvn-Z-vl S-t 2 4'- amides and esters. mineral oils such as kerosene. light Dichlorophenoxy) 2-r1itrobenzoate. oil. oils. and medium oils and vegetable oils such as cotton- 3l. l-Pentyl-Z-propynl 5-(2.4-Dichlorophenoxy)-2- seed oil.

nitrobenzoate. oil. I In practice. herbicidal application is measured in 32. lEthynylcyclohexyl -(2'.4'-Dichlorophenoxy)- terms of pounds of herbicide applied per acre. The Z-nitrobcnzoate. oil. compounds of this invention are effective herbicides 33. Propyn-Z-yl Z-Nitro-S-(Z'AJV- when applied in herbicidal amounts. i.e.. at rates bctrichlorophenoxy) benzoate. oil. tween about 0.2 pound and about 10 pounds per acre. 34. 3-Butyn-2-yl Z-Nitro-S-(ZA'Jf- Although the present invention has been described trichlorophenoxy) benzoate, oil. with preferred embodiments, it is to be understood that 35. Propyn-Z-yl 5-(2',4'dichloro-b'-fluorophenoxy)- modifications and variations may be resorted to. with- Z-nitrobenzoate, oil. out departing from the spirit and scope of this inven- 36. 3-Butyn-2-yl 5-(2.4-dichloro-6- tion. as those skilled in the art will readily understand. fluorophenoxy)-2-nitrobenzoate. oil. Such modifications and variations are considered to be The herbicidal effectiveness of the compounds of Exwithin the purview and scope of the appended claims. amples 2436 for Herbicidal Effectiveness is shown in What .is claimed is: I the following Table III, l. A compound having the formula:

TABLE III PRE/POST EMERGENCE GRASSES BROADLEAVES CROPS EXAMPLE LBS/ACRE CG JG BG BW VL TP CT I CN EN ISO/I00 4 0/40 0/ 0/ 0/ 50/ /90 0/60 0/ 0/80 27. 8 0/40 0/ 0/ 0/ 70/ 70/50 0/0 0/ 0/60 4 0/20 0/ 0/- 40/- 30/- 0/40 0/0 0/ 0/30 28. 8 30/0 0/ 0/ 60/ 50/ 70/90 OI l 00 0/ l/l00 4 0/0 0/- 0/ 50/ 40/ 70/0 30/100 0/ 30/l00 29. 8 50/0 0/ 30/- 0/ 70/ 100/90 40/100 ol- The compounds of this invention can be applied in COOR various ways to achieve herbicidal action. They can be O N applied per se. as solids or in vaporized form. but are preferably applied as the toxic components in pestici- 0 da] compositions of the compound and a carrier. These compositions are preferably applied directly to the soil and incorporated therewith. The compositions can be applied. as granulars or dusts; as liquid sprays. or as wherein X is halogen. Izis l to 3. and R is alkyl gas-propelled sprays and can contain. in addition to a (c f cycloalkyl (cg-(.1 or unsaturated hyd carrier. additives such as emulsifying agents. binding ah (C. gents. gases compressed to the liquid state. odorants. 2. A compound of claim l. wherein said compound stabilizers. and the like. A wide variety of liquid and is Cyclohexyl S-t2.4dichlorophenoxy)-2- solid carriers can be used. Non-limiting examples of nitrobenzoate.

6. A compound of claim 1., wherein said compound is 2-Methyl-3-butyn-2-yl -(2.4'-dichlorophenoxy)-2- nitrobenzoate. v

7. A compound of claim 1, wherein said compound is 3-Butyn-2-yl 5-(2,4-dichloro-6-flurophenoxy)-2- nitrobenzoate.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT N0. 3,907,866

DATED September 23, 1975 |NVENTR(5) 1 Robert J. Theissen it is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below: 6

Col. 1, line 27 "cycloalkyl (03-0 0) esters, do not appear should be --cycloalk:yl (C -C8) esters, as well as the unsaturated hydrocarbyl (0 -6 esters, do not appear.

Q Col. 1, line 5 1 I "H0 should be --E01--.

001. 2, line 23 "R groups" should be --"R" groups Col. 2, line 17 0:0 should be 0=0--.

col. 1, Table 1 "Exam le 1, under 0T, "02/30" should be Col. 6, line Exam 1e 21 under 0.3 ppm "3-5" should be Q Col. 6, line 61 CH" should be --V'0'f CH-.

" 0 0" should be 4fd=0--.

col. 8, Table 111 Example 2M, under BN, "180/100" and "180/100" should be --O/lOO-- and --O/lOO-.

Col. 8, Table III Example 25, under CT, t/9O" should be Col. 8, Table 111 Example 26, under BN, "180/100" should be Col. 8, Table 111 Example 28, under B1\L "/100" should be 0 100--. Col. 8, Table III Example 29,I twice, and Example 32, under BN,

"180/100 should be 0/100--.

Signed and Sealed this second Day of March 1976 [SEAL] Attest: D

RUTH C. MASON C. MARSHALL DANN Arres ing Offic I Commissioner ofParents and Trademarks 

1. A COMPOUND HAVING THE FORMULA
 2. A compound of claim 1, wherein said compound is Cyclohexyl 5-(2'',4''-dichlorophenoxy)-2-nitrobenzoate.
 3. A compound of claim 1, wherein said compound is 2-Octyl 5-(2'',4''-dichlorophenoxy)-2-nitrobenzoate.
 4. A compound of claim 1, wherein said compound is Cyclohexyl 2-Nitro-5-(2'',4'',6''-trichlorophenoxy)benzoate.
 5. A compound of claim 1, wherein said compound is 3-Butyn-2-yl 5-(2'',4''-dichlorophenoxy)-2-nitrobenzoate.
 6. A compound of claim 1, wherein said compound is 2-Methyl-3-butyn-2-yl 5-(2'',4''-dichlorophenoxy)-2-nitrobenzoate.
 7. A compound of claim 1, wherein said compound is 3-Butyn-2-yl 5-(2'',4''-dichloro-6''-flurophenoxy)-2-nitrobenzoate. 